Apparatus for producing seamless pipe



Sept 17, 1963 H. LlNDl-:MANN 3,103,718

APPARATUS PoR PRoDUcING sEAMLEss PIPE v ww' Fig. 7

Sept. 17, 1963 H. LINDEMANN 3,103,718

APPARATUS FOR PRODUCING SEAMLESS PIPE Filed April 27, 1959 3 Sheets-Sheet 2 H. LINDEMANN APPARATUS FOR PRODUCING SEAMLE'SS PIPE Filed April 27, 1959 sept. 17, 1963 3 Sheets-Sheet 3 United States Patent O 3,103,7l8 APPARATUS FOR PRDUCING SEAMLESS IWE Hans Lindemann, Bieleteld, Germany, assigner to Th. Carlow d.' Co., Bieleteid, Germany, a firm of Germany Filed Apr. 27, 1959, Ser. No. 869,644 Claims priority, application Germany Apr. 2S, 1953 3 Claims. (Cl. 22--57.2)

The present invention relates to a new method and apparatus for producing rod-shaped and tubular stock and, more particularly seamless pipes, especially of iron or steel.

Prior to this invention, the production of seamless pipe has been a very complicated, protracted, and expensive process. It generally consisted `of iirst inserting an ingot, usually in `a white-hot condition, into a press and torming a bore in the ingot -by means of a ram, and then passing the ingot through a drawing die to form a pipe. An economic production of seamless pipes according to this method requires them to be made of a relatively short length of about l to 15 m. Such a pipe is then reduced in diameter and extended in a rolling mill, cooled, then .subjected to a pressure test, straightened, and then further treated in accordance with its particular purpose.

It is an object of the present invention to simplify the production of rod-shaped Iand tubular stock and especially of seamless pipe, and to reduce `the cost of such production considerably.

A further object of the invention is to provide a new method of extruding rod-shaped and tubular :stock `and especially seamless pipe so `as to permit a complete production of such materials within a very short time and of practically any desired length.

For attaining these objects, the new method generally consists in subjecting a liquid material, preferably iron or steel, to a very high pressure by means of a gas, prefer ably an inert gas, in then heating or cooling the material to Iattain a viscous condition, land in then extruding such viscous material to form rod-shaped or tubular stock and especially seamless pipe.

The apparatus for carrying out the method according to the invention preferably consists of a cylindrical container with at least one inlet land one outlet, wherein the latter consists of yan exchangeable extrusion nozzle which may be equipped with a movable mandrel which is adapted to be passed into the nozzle and to be moved therein, and which is provided with cooling means.

The proper execution of the new method further requires suitable means for cooling the inner wall of the container `as well as the extrusion nozzle, and means for heating the contents of the container, as well as means for determining and measuring the viscosity of the material use for producing the rod-shaped or tubular stock.

According to the invention, the material is inserted in a liquid condition into a pressure-resistant container, which is provided with means for heating and cooling the same; it is then degassed in the container and thereafter subjected to a high pressure by means of an inert, gas, whereupon, as soon as the material has attained the proper degree of viscosity, it is extruded by such pressure from the container through the extrusion nozzle which is provided centrally thereof with a hollow mandrel. It is thus possible to pro-duce seamless pipe of many times the length which was previously attainable, vand to attain them im- "ice mediately in a finished condition, bright-drawn Iand of the desired -inner and outer diameters. `Such pipes may now be attained at a rate of production of, for example, 200 to 50()y m./min.

It has been -found advisable to suspend the container, and preferably a-lso the mandrel therein, so as to be movable backwards and forwards Iin its axial direction and also to be rotatable about its axis. The mandrel which extends through the extrusion nozzle is preferably made of a tubular shape so as to be cooled from the inside by a cooling agent which is discharged therefrom in the direction of and through the pipe to be formed. This also applies to the cooling agent for cooling the container, and the pipe as it is lbeing extruded from the extrusion nozzle wil-l thus be surrounded at the inside and `outside by a cooling vagent which preferably consists of an inert gas to prevent scaling of the pipe. For ascertaining the degree of viscosity of the material within the container, it is .advisable to determine the frictional resistance prevailing 'between the material and a wall `surface which is movable relative thereto. This wall surface may consist, for example, of the hollow mandrel which is associated with the extrusion nozzle. However, it is also possible to measure and indicate the oscillatory movements `of the container and to determine therefrom the degree of viscosity of the material. In order to render the pipe production still more economical, it is advisable to combine several containers, for example, on a turntable, and to extrude a p-ipe 4from one container, while in the meantime the liquid metal is iilled into and prepared in the other containers.

Further objects, features, and advantages of the present invention will be apparent from the following detailed description thereof, particularly when read with reference to the accompanying diagrammatic drawings, in which- FIGURE l shows a side view, partly `in cross section, of an apparatus for producing seamless pipes according to the new invention;

FIGURE 2 shows a partial cross section taken along line II-II of FIGURE l;

FIGURE 3 shows a view, partly in section, of a part of the apparatus according to FIGURE 1, as seen in the direction of the arrow HI therein;

VTFIGURE 4 shows a plan view of a turntable on which four apparatus according to FIGURE 1 are mounted; while FIGURE 5 shows a side View of FIGURE 4, partly in a cross section taken along line V-V of FIGURE 4.

Referring to lthe drawings, lthe particular embodiment of the invention as shown therein consists of a container l for receiving and preparing the material lfor the extrusion process. This container 1 has three openings 2, 3, and 4. The opening 2 serves as an inlet for supplying the liquid metal 5, fas well as .the inet gas under pressure into the container 1. The upper yopening 3 serves as an outlet through which the container is evacuated and oxidizing gases contained in the liquid metal are extracted. T he bottom opening 4 inally serves as an outlet through which the molten material 5 is `extruded to lfor-m a seamless pipe. Inlet opening 2 is connected -by one lor more suitable valves to the container I in which fthe metal is heated to maintain it in a liquid condition, while opening 3 is similarly connected by valves to the suction pump for evacuating the gases from the metal in container 1.

The container is preferably provided with an electric inductive-heating system as indicated by ya coil 6, and the extrusion nozzle 7 which surrounds the outlet opening 4 is provided with a separate heating coil 8 and mounted in container 1 so as to be exchangeable. For opening and closing the outlet 4, various means may 'be used. In the embodiment of the invention as illustrated, outlet 4 may be closed by moving a hollow tubular shaft or mandrel 9 which has -a plug portion thereon in the downward direction as indicated by the arrow 10. This tubular mandrel 9 and the container 1 are cooled either by water or by an inert Igas which ilows in the direction indicated by the arrows -11 and 12. The cooling water or gas which is passed through the hollow mandrel 9, as well as the gas owing between container 1 and the outer wall 13 emerge in the same direction in which the seamless pipe 14 is extruded from the container when the annular aperture between the hollow mandrel 9 `and extrusion nozzle 7 is opened.

At the beginning of the operation, the outlet 4 is tightly closed and the inside of container 1 is completely evacuated. The liquid material, for example, steel, is then filled through a valve into the container and the oxidizing gases are extracted therefrom. Thereupon the inert gas is fed under a high pressure into the container. The container is then cooled to such as extent that the material therein, for example, the steel, has the desired temperature and a certain degree of viscosity. The hollow mandrel 9 and container 1 may be subjected to longitudinal and rotary vibrations in order to agitate the liquid steel and eirect a thorough mixture thereof. After the steel has attained the desired degree of viscosity, mandrel 9 will be shifted `to a position in which the material would start to How out between the shaft and the container 1 if the steel was not too viscous. The container is then heated until the steel has become sutiiciently uid to emerge from the extrusion nozzle, and such heating is carried out automatically so that the extrusion speed will `remain constant. Since the steel in container 1 is subjected lto pressure, it will liquefy at a lower temperat-ure in accordance with the amount of pressure applied, for example, at a temperature which is C. lower than the normal melting point if the pressure applied amounts to 1000 atm. Consequently, when the steel emerges from the extrusion nozzle, it will solidify sooner than if it was not subjected to such pressure. 1f the seamless pipe to be produced is for 'any reason to be made shorter than the amount of material in container 1 would allow, the extrusion nozzle only has to be quickly and strongly heated 4so that the material will fully melt at that point and the pipe formed will tear ot at the nozzle. It is then only necessary to close the extrusion nozzle to prevent the liquid material from ilowing out of the container. Naturally, the extrusion of the metal from the container may also be interrupted solely by closing the extrusion nozzle.

If several containers 1 of a type as shown in FIGURE 1 are mounted on a turntable, as illustrated in FIGURES 4 and 5, the continuous production of the pipes does not need to be interrupted because one extrusion nozzle or the mandrel which is associated therewith has been damaged and has to be exchanged. Such exchange may be easily carried out while the extrusion process continues on another container.

Although the means for supplying the molten metal or the cooling agent, that is, the cooling iiuid or the insert gas, or the means for reciprocating the container and the mandrel and the specific manner of arranging the various containers relative to each other may be in accordance with many dilerent designs, a few suitable embodiments of .the invention will now be described W-ith respect to those elements illustrated in the drawings which have as yet not been particularly mentioned.

The inlet 2 of container 1 is connected to an inlet pipe 15 which carries an open funnel-like container -16 into which the liquid metal is poured. The opening -17 of container 16 may be closed by a plug 18 which may be operated by a lever 20 which is pivotably mounted at 19. Inlet pipe 15 branches oif into a pipe 21 which is connected by a tlexible hose 22 and a control valve 23 to a surge tank 24 which is supplied by a reciprocating pump 25 driven by a motor 27 with an inert gas which is drawn from a suitable source of supply through a pipe 26.

The outlet 3 is connected by a pipe ilange 28 to a hose connection 29 lon which a flexible hose 30 is secured which is connected through a pipe 31 and a control valve 32 to a reciprocating pump 33 which is driven by a motor 35 and operates as a suction pump to evacuate the container 1 and then also the oxidizing gases of the molten metal therein.

The inside of the hollow mandrel 9 communicates through a hose coupling 36 and a tlexible hose 37 with a pipe 38 which may be connected, on the one hand, by a control valve 39 to pipe 31 and, on the other hand, `by a control valve `40 to a pipe 41 which is connected to the pressure side of a rotary pump 42 which is `driven by a motor 43. The suction side of pump 42 is connected to a pipe 44 with a suction strainer 45 thereon which yis immersed in a cooling iluid 46 in a container 47. The annular chamber 48 4formed between the container 1 and the outer wall 13 is likewise connected to pipe 38 through a pipe flange 49, a flexible hose 50, and a hose connection 51.

lf the cooling fluid is to be passed through the hol low mandrel 9, control valve 39 is closed and control `valve 40 is opened, whereupon motor 43 is switched on. Since chamber 43 around container 1 communicates with pipe 33 through the exible hose 50, the cooling fluid, for example, water, also flows through chamber 4S. If chamber 48 and t-he inside of mandrel 9 should be supplied with an inert gas in order to protect the extruded pipe from scaling, both control valves 32 and 40` should be closed. After the liquid metal in container k1 has been `degassed while control valve 32 is still open and control valve 39 should then be regulated so that the tainer 1 through the opening 3, hose 30, pipe 31 and the -opened control valve 39 and hose 37 to the inside of mandrel 9 and also through hose 50 into chamber 48. The pressure of the gas in surge tank 24` and the control valve 39 should then be regulated so that the pressure in container 1 will still be of a suflicient strength to -force the viscous material 5 through the extrusion nozzle 7. Of course, if it is desired that lthe iiow of inert gas along the walls of container 1 and nozzle 7 and along the extruded pipe 14, as well as through mandrel 9 and through the extruded pipe should exert a more effective cooling action, the 'gas after emerging from outlet 3 of the container may iirst be passed through a suitable cooling system, not shown, or it may be supplied to chamber 48 and mandrel 9 from a separate SOLU'CC.

Above the container 1, the hollow shaft of mandrel 9 carries a hand-wheel 52 which engages into an annular groove 53 in the outer surface `olf this shaft so as to be rotatable thereon, but nonslidable in its `axial direction. This handwheel 52 has a threaded portion 54 thereon which .engages into a threaded bushing 55. This bushing 55 is slidably mounted on the mandrel shaft 9 to guide the same and is, in turn, :guided within a bushing 73 which is integrally secured to and connects a pair of brackets 63 and 69 on the upper part of a frame 7). Bushing 55 carries a pair of trunnions 56 and 57, each of which carries a slide member 58 or 59, respectively. As illustrated in `FIGURE 3, slide members 58 and 59 are slidablc in `elongated apertures 60 and 61 in brackets 63 and 69. Between brackets 68 and 69 and bushing 55, trunnions 56 and 57 are rotatably mounted on :the lower ends of a pair of connecting 4rods 62 and 63, the 4upper ends of which are rotatably connected to a pair of eccentrics 64 and 65 which are rigidly secured to a shaft 67. This shaft 67 is rotatably mounted within trame 79 and driven by a motor 66 which is also mou-nted on frame 7i); Since the speed of rotation of shaft 67 is dependent upon the viscosity of the material in container 1 and the lfriction encountered by mandrel 9 therein, the readings on a speedometer 66 provided on motor 66 will serve as an indication of the degree of the viscosity `or iluidity of the material.

When shaft 67 is not being driven by motor 66, mandrel 9 may be raised yor lowered by turning orf :the hand- Wheel 52 for the purpose of opening or closing the extrusion nozzle '7. In the embodiment of the invention according to FIGURE 1, handwheel 52 is shown as being turned to a position in which mandrel 9 is rais-ed :from the ex-tnusion nozzle 7 so that the liquid material 5 can be extruded through nozzle 7 in che down-ward direction. Lf shaft 67 is then rotated by motor 66, mandrel 9 will be reciprocated in a vertical direction.

It is advisable to move the mandrel 9 not only upwardly and downwardly, but also to give it torsional vibrations. This may be effected by reciprocating the mandrel about its longitudinal axis. rl'lhe upper end of mandrel 9 is for this purpose provided -with a Agroove 71 which extends parallel to the axis of the mandrel. An annular disk 72 which is mounted vvithin the bushing 73 on brackets 68 and 69 engages with an inner tooth into groove 71 and is, in turn, connected by a tnunnion 74 and a ball-and-socket joint 75 to a connecting rod 76 which is eccentrically mounted by another ball-and-socket joint 77 on a disk 78 which is secured to the shatit 79 or a motor Si). Thus, mandrel 9 may be reciprocated in the vertical direction by motor 66 and in a rotary dinection about its longitudinal axis by motor Si?.

Ln a similar manner it is also possible to reciprocate the container 1 and the router wall 13 with the various parts thereon both in the vertical and rotary directions. In the particular embodiment of the invention as illustrated in the drawings, the vertical reciprocation of these parts is effected by a bifurcated rocker arm 81 which is pivotable upwardly and downwardly about a trunnion 82 by means of an eccentric 84 on a shaft 83. The eccentric 84 is rotatably mounted in a slide member S5 which is silidable late-rally in an elongated aperture 86 in rocker arm 81. Shaft 83 may be driven by a motor 87. On its lower tubular part, the outer wall of chamber 48 is provided with a flange 88 which rests on a thrust bearing 89 for supporting the entire container 1 including chamber 48. This thrust bearing :89 is, in turn, supported by an annular part 90' fwhich, las shown in FIGURE 3, lis pivotably mounted on trunnions 91 and 92 between the two arms rolf the bifurcated rocker arm 81.

For reciprocating the container 1 including the chamber 43 about its vertical axis, the outer wall 13 of the latter m-ay be provided with a lateral extension 93 which is connected by a ball-andsocket joint 94 `on one end of a rod 95 and another ball-and-soclcet joint 96 on :the other end to an eccentric on a disk 97 which is rotatably mounted in a bearing 98 and driven by a motor 99.

All of the elements as above described are supported by a drame 16)- which is mounted on a suitable loundation 101.

ln order to render the production of seamless pipes still more economical, it is also possible, instead of applying a single apparatus as shown in FIGURE 1 and mounting the same on a stationary frame 199, to provide a plurality of such apparatus on a turntable d. The necessary preliminary operations preceding the actual extrusion of the pipe or pipes, 'for example, the evacuation of the container 1, the tilling of the molten metal therein, the degassing of the metal, the application of the gas pressure, etc., may then be carried out successively in each apparatus at the diierent stops of the turntable 1Gb so that very little time will be lost between the actual extrusion operations. Since the individual elements of one complete apparatus have already been adequately described with referenc to -FIG- URES 1 and 2, a diagrammatic illustration of the arrangment of several apparatus on a turntable 100', as shown in FIGURES 4 and 5, will be sumcient to explain this feature of the invention. The turntable 101) is rotatably mounted on a central trunnion 103 in a base 102 and its weight is supported near its outer periphery by rollers 105 which are movable on a circular rail 104.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications Within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim l. A casting and extruding apparatus, comprising, in combination, a container having inlet means .for introducing a metal into said container, and an outlet nozzle; first closure means =f0r closing said inlet means; an elongated member extending into said container and having a projecting portion .projecting out of the same; second closure means for closing said outlet nozzle; means on said container for varying the temperature of a metal therein; means for introducing a gas under high pressure into the container so that the metal assumes a selected viscous condition at a selected temperature and pressure; a motor operatively connected to said projecting portion of said elongated member for reciprocating the same so that the resistance encountered by said elongated member in the metal increases as the metal assumes a viscous condition; measuring means connected to said motor `for measuring the speed of said motor so that the reduction of the motor speed due to the greater resistance of the viscous metal is a measure of the viscosity of the metal; and means .for opening said second closure means when said measuring means indicate said selected viscous condition whereby the metal is extruded through said outlet nozzle and assumes a solid state under atmospheric pressure.

2. An apparatus as set forth in claim 1, wherein said elongated member is tubular and said second closure means is a tubular closure portion of said elongated member and :forms with said outlet nozzle an annular extrusion opening; and means `for introducing a coolant into said projecting portion so that the coolant ows through said elongated member, said closure portion, andin extrusion direction through a tubular body extruded through said annular extrusion opening.

3. A casing and extruding apparatus, comprising, in combination, a container having inlet means for introducing a metal into said container, and an outlet nozzle; first closuremeans for closing said inlet means; second closure means for closing said outlet nozzle; means on said container for varying the temperature of a metal therein; means for introducing a gas under high pressure into the container while said first closure means is closed so that the pressure in said container is raised to said high pressure while the metal assumes a selected viscous condition at a selected temperature and pressure; means for measuring and indicating the viscous condition of the metal to determine said selected viscous condition,

and including a movable member located in said con- (References on following page) References Cited in the le of this patent UNITED STATES PATENTS Straus et al. Dec. 13, 1904 Lane Aug. 4, 1925 Brennan Sept. 25, 1951 Weiblund Dec. 11, 1951 Dickson May 10, 1955 Whitaker July 17, 1957 Janco Sept. 16, 1958 Pond Oct. 6, 1959 S FOREIGN PATENTS Belgium Feb. 15, 1951 Germany May 28, 1953 France Apr. 10, 1958 Switzerland Nov. 16, 1943 Switzerland Sept. l, 1948 OTHER REFERENCES Fowle: Smithsonian Physical Tables, second reprint of Seventh Revised Edition, Washington, 1923, page 200. 

1. A CASTING AND EXTRUDING APPARATUS, COMPRISING, IN COMBINATION, A CONTAINER HAVING INLET MEANS FOR INTRODUCING A METAL INTO SAID CONTAINER, AND AN OUTLET NOZZLE; FIRST CLOSURE MEANS FOR CLOSING SAID INLET MEANS; AN ELONGATED MEMBER EXTENDING INTO SAID CONTAINER AND HAVING A PROJECTING PORTION PROJECTING OUT OF THE SAME; SECOND CLOSURE MEANS FOR CLOSING SAID OUTLET NOZZLE; MEANS ON SAID CONTAINER FOR VARYING THE TEMPERATURE OF A METAL THEREIN; MEANS FOR INTRODUCING A GAS UNDER HIGH PRESSURE INTO THE CONTAINER SO THAT THE METAL ASSUMES A SELECTED VISCOUS CONDITION AT A SELECTED TEMPERATURE AND PRESSURE; A MOTOR OPERATIVELY CONNECTED TO SAID PROJECTING PORTION OF SAID ELONGATED MEMBER FOR RECIPROCATING THE SAME SO THAT THE RESISTANCE ENCOUNTERED BY SAID ELONGATED MEMBER IN THE METAL INCREASES AS THE METAL ASSUMES A VISCOUS CONDITION; MEASURING MEANS CONNECTED TO SAID MOTOR FOR MEASURING THE SPEED OF SAID MOTOR SO THAT THE REDUCTION OF THE MOTOR SPEED DUE TO THE GREATER RESISTANCE OF THE VISCOUS METAL IS A MEASURE OF THE VISCOSITY OF THE METAL; AND MEANS FOR OPENING SAID SECOND CLOSURE MEANS WHEN SAID MEASURING MEANS INDICATE SAID SELECTED VISCOUS CONDITION WHEREBY THE METAL IS EXTRUDED THROUGH SAID OUTLET NOZZLE AND ASSUMES A SOLID STATE UNDER ATMOSPHERIC PRESSURE. 